The present invention relates to composite structures, more particularly to composite structures (e.g., composite armor structures) that include ceramic material and non-ceramic material.
Many composite structures are designed to serve primarily a structural purpose. Nevertheless, it may be desirable that a composite structure have one or more attributes beside structural supportability, such as armor protectiveness or electromagnetic effectiveness. The current state of the art is such that the ability to simultaneously achieve double performance or triple performance (e.g., structural and/or ballistic and/or electromagnetic performance) in a composite structure is limited. Fabrication of dual-performance composites or tri-performance composites has been problematical, and difficulties have increased with increasing numbers of different performance objectives. In particular, there is a dearth of information in the literature on how a single composite structure may be imbued with all three characteristics, viz., structural and ballistic and electromagnetic characteristics. Effective integration of both electromagnetic functionality and ballistic functionality within a composite structure remains elusive in the art.
The traditional approach to imparting armor (e.g., ballistic armor) character or electromagnetic character to a structural composite involves use of auxiliary or “parasitic” structure. That is, to enhance structural performance with electromagnetic or armor-protective (e.g., ballistic) performance, electromagnetically or armor-protectively functional materials are added to the exterior of structural composite materials. For instance, ceramic armor plates are bolted to the outer surface of a composite structure. A more integrative approach to lending armor-protective or electromagnetic performance to a composite structure has been considered in the art. In theory, at least, electromagnetic or ballistic materials may be integrated into the stack of a composite structure. However, the integrative approach has apparently seen scant practical success. Integration of disparate materials brings new challenges, such as pertaining to performances of individual materials, and to interactions between plural materials.
Military armor applications include land vehicles, marine vehicles, air vehicles, stationary structures, and personnel. Armor is used typically to protect against impact by a projectile, such as a ballistic body (e.g., small arms fire) or an explosive fragment (e.g., shrapnel from a bomb blast). Various armor constructions and configurations are known that utilize ceramic material. Some armor systems and methods have been disclosed that involve implementation of discrete ceramic elements in combination with non-ceramic material. For instance, Shih et al. U.S. Pat. No. 6,532,857 B1 issued 18 Mar. 2003 entitled “Ceramic Array Armor,” incorporated herein by reference, disclose an armor system that includes an elastomeric matrix (e.g., binder) material and, encapsulated therein, plural ceramic tiles arrayed along a common surface and spaced apart from one another.
As broadly defined, a ceramic material is an inorganic nonmetallic material made from a compound of a metal and a nonmetal. According to the broad definition adopted herein, a ceramic material can be crystalline, or can be partly crystalline and partly amorphous (e.g., “glass-ceramic”). Conventional ceramic armor materials include aluminum oxide (commonly called “alumina”), silicon carbide, boron carbide, and titanium carbide. Among other examples of ceramic materials are tungsten carbide, magnesium oxide, titanium dioxide, and porcelain.